move compilationStarted event listener

src/app/tabs/compile-tab.js

@@ -114,6 +114,7 @@ class CompileTab {
       compileIcon.setAttribute('title', 'idle')
     })
     appEvents.compiler.register('compilationStarted', function start () {
+      errorContainer.innerHTML = ''
       compileIcon.classList.remove(`${css.bouncingIcon}`)
       compileIcon.classList.add(`${css.spinningIcon}`)
       compileIcon.setAttribute('title', 'compiling...')
@@ -139,10 +140,6 @@ class CompileTab {
     function contractNames (appAPI, appEvents, opts) {
       var contractsDetails = {}
 
-      appEvents.compiler.register('compilationStarted', () => {
-        errorContainer.innerHTML = ''
-      })
-
       appEvents.compiler.register('compilationFinished', function (success, data, source) {
         // reset the contractMetadata list (used by the publish action)
         contractsDetails = {}